I think I found the source of the problem mentioned before: When I played the first time, I had some ships just over one of the tiles where drowns are supossed to appear. So, as mentioned, only 1 drown appeared. This time I started from a long way back saved game and when I razed the capital, 2 drowns appeared. I killed them and the option screen appeared etc.... I choosed Malakim.
BUT........ now I have another problem. When I go play scenarios and choose "Into the desert" the game crashes.
Any ideas how to solve this?
I can confirm this solution, I was getting crash to desktop after the razing, I loaded the autosave and sure enough there was a lanun ship in one of the spawn points for the drown. I waited until it moved to raze the city and hurrah! no crash.